Will Jones created ARROW-16761: ---------------------------------- Summary: [C++][Python] Track bytes_written on FileWriter / WrittenFile Key: ARROW-16761 URL: https://issues.apache.org/jira/browse/ARROW-16761 Project: Apache Arrow Issue Type: New Feature Components: C++, Python Affects Versions: 8.0.0 Reporter: Will Jones Fix For: 9.0.0
For Apache Iceberg and Delta Lake tables, we need to be able to get the size of the files written in bytes. In Iceberg, this is the required fieldĀ {{file_size_in_bytes}} ([docs|https://iceberg.apache.org/spec/#manifests]). In Delta, this is the required field {{size}} as part of the Add action. I think this could be exposed on [FileWriter|https://github.com/apache/arrow/blob/8c63788ff7d52812599a546989b7df10887cb01e/cpp/src/arrow/dataset/file_base.h#L305] and then through that [WrittenFile|https://github.com/apache/arrow/blob/8c63788ff7d52812599a546989b7df10887cb01e/python/pyarrow/_dataset.pyx#L766-L769]. But lower-level than that I'm not yet sure. {{FileWriter}} owns its {{OutputStream}}; would {{OutputStream::Tell()}} give the correct count? -- This message was sent by Atlassian Jira (v8.20.7#820007)